A key design parameter for a transistor device is the current delivered at a given designed voltage. This parameter is commonly referred to as the drive current or saturation current (IDsat). One factor that has an effect on the drive current is the carrier mobility of the channel region. Increases in the carrier mobility in the channel region result in increases in the drive current. The carriers in n-MOS and p-MOS transistors are electrons and holes respectively. The electron mobility of the channel region in n-MOS devices may be increased by exposing the region to a uniaxial tensile strain. Alternatively, the hole mobility of the channel region in p-MOS devices may be increased by applying a uniaxial compressive strain on the channel region.